Outlaw IDE
The #1 IDE for Corona SDK game and biz apps makes development even faster (free version available).
Super Sprite Bundle
Royalty-free graphics for 2D games - animated characters, tile sets, etc.
App Vault
Biz app developers - these help you create stunning apps in half the time while saving you tons of money you would have otherwise spent hiring designers.
GameDevMarket.net
Great quality (but budget priced) 2D and 3D artwork you can use in your own games.
Pathfinding Tutorial
Use Corona SDK and the free Jumper library to do A* pathfinding in your games - over 60 minutes of video + sample code!